Help me out with something here. I read on here about a month or two ago that implied odds are pointless preflop, or basically a myth. Any truth to this and if so, why.

I would say no, they're not pointless, but they are probably overvalued. If a good tight player raises your blind and you have 86s, you're reasoning for calling can't just be, my hand is worse than his, but if I hit I should be able to stack him.

You also have to factor in that he's a good player, which means even if you hit your hand, he might not stack off. You also have to factor in your inferior position. It's better to call with weak hands in position. It's also better to be raising these hands in position than calling out of position. You can't just rely on implied pot odds to make money on these. You also have to steal some blinds/pots with them too. It also helps you get paid off with your strong hands when you play a wider range. Just don't get carried away.

Obviously, if you're seen this opponent stack off with TPTK, even on dangerous looking boards, it's easier to value those implied odds.

I also think preflop implied odds have more value in a cash game than in 20-60 bb average stack tournament.

preflop pot odds maybe?
This thread

Maybe that was the discussion I was thinking of.

If that's the topic, see my thoughts in this infamous 3 queens thread.

I totally disagree that they arent critical PF as well..in fact they are the basis for Harringtons M theory, and why you play hands differently with different relative stacks. Eg you dont set mine or play suited connectors with an M<10 because you dont have the implied odds to justify playing an 8.5:1 shot.

The first part of Professional NLH is an extensive discussion of pot commitment and stack to pot ratios, which are really just long winded implied odds discussions.

implied odds figure into every single decision you make preflop unless you are going all in or calling all in.